Method and apparatus for electrospark alloying

The present invention relates generally to a method and apparatus for electrospark alloying (ESA). More particularly, in one embodiment of the present invention, the electrospark alloying defines a micro-welding process for depositing a portion of the rotating electrode onto the work piece to form a fully dense metallurgical bond therebetween. Although the invention was developed for the repair of metallic gas turbine engine components, certain applications may be outside of this field. An electrospark alloying apparatus includes a main body member, a collet coupled to the main body member, and a heat sink adjacent the collet. The collet is adapted to receive and hold a consumable electrode. The apparatus can also include a drive for rotating the electrode. Further, the apparatus can include an inert gas supply and a discharge opening in the main body member for facilitating lamellar gas flow of insert gas from the inert gas supply around the electrode. A method of electrospark alloying includes electrospark alloying a workpiece with a consumable electrode and cooling the electrode during the electrospark welding.